diff --git a/src/scripts/clipboard.inline.ts b/src/scripts/clipboard.inline.ts
index 6d59a9f..e2a3e71 100644
--- a/src/scripts/clipboard.inline.ts
+++ b/src/scripts/clipboard.inline.ts
@@ -18,7 +18,7 @@ document.addEventListener("nav", () => {
       button.type = "button";
       button.innerHTML = svgCopy;
       button.ariaLabel = "Copy source";
-      function onClick() {
+      const onClick = () => {
         navigator.clipboard.writeText(source).then(
           () => {
             button.blur();
@@ -30,7 +30,7 @@ document.addEventListener("nav", () => {
           },
           (error) => console.error(error),
         );
-      }
+      };
       button.addEventListener("click", onClick);
       window.addCleanup(() => button.removeEventListener("click", onClick));
       el.prepend(button);
diff --git a/src/transformer.ts b/src/transformer.ts
index 613dd94..1c16dfc 100644
--- a/src/transformer.ts
+++ b/src/transformer.ts
@@ -1,7 +1,7 @@
 import rehypePrettyCode from "rehype-pretty-code";
 import type { Options as CodeOptions, Theme as CodeTheme } from "rehype-pretty-code";
 import type { QuartzTransformerPlugin, JSResource, CSSResource } from "@quartz-community/types";
-// @ts-ignore
+// @ts-expect-error - inline script import handled by Quartz bundler
 import clipboardScript from "./scripts/clipboard.inline";
 import clipboardStyle from "./styles/clipboard.scss";
 
diff --git a/types/globals.d.ts b/types/globals.d.ts
new file mode 100644
index 0000000..72edf9c
--- /dev/null
+++ b/types/globals.d.ts
@@ -0,0 +1,3 @@
+interface Window {
+  addCleanup(fn: (...args: unknown[]) => void): void;
+}